78 CIRCULAR 9 7 7. U. S. DEPARTMENT OF AGRICULTURE 



waistband, and fly of the trousers, the socks above the shoe tops, and 

 the eyelets of the shoes (fig. 31). For fleas or ticks the trouser legs 

 should be treated as far as the knees or even to the waist. 



For protection of troops during prolonged field exposure, the im- 

 pregnation of entire uniforms is considered the most practical method 

 of utilizing repellents. Either emulsions or solutions in such volatile 

 solvents as acetone, xylene, or dry-cleaning compounds may be used. 

 Solutions and emulsions gave about equal results in tests with tick 

 repellents. Generally an emulsion is recommended, because water for 

 dilution can be obtained at the time and site of treatment, so that 

 transportation of only the concentrate is required. Occasionally mass 

 impregnation may be done most conveniently with solutions in dry- 

 cleaning equipment. 



The individual repellents are applied at the rate of about 2 grams 

 per square foot of cloth, which is equivalent to about 75 ml., or 2){ 

 fluid ounces, to a two-piece uniform. A pair of socks should be in- 

 cluded with the uniform. The minimum volume of liquid required to 

 saturate such an outfit is about Z% pints, and the proper amount of 

 repellent is contained in this quantity of a 5-percent solution or emul- 

 sion. 



Figure 31. — Applying ehigger repellent to trouser cuff. 



